Apples and Oranges: The uses and abuses of EEG in market research
Imagine you own a fruit stand. Okay? Well also imagine that due to your immensely busy schedule, you don’t have time to tally up the fruit sold at the end of the day, so you hired someone to do it for you. The only problem is that this person has a really hard time telling apart apples and oranges and counts them all as the same thing. What would you do in this scenario? Would you rely on his guesses, or would you hire someone who actually knows the difference?
Now imagine that instead of fruit, we are talking about dimensions of emotional response. The apples represent emotional valence, attractiveness vs. aversiveness, which is on a continuum of positive to negative. The oranges represent motivation and willingness to engage, ranging from approach to avoid. These are two very different concepts, each needing its own unique means of measurement. We don’t want to compare apples to oranges.
There are people out there practicing neuromarketing who use EEG, or electroencephalography, to measure these things. Their method rests on the idea that asymmetry between the left and right frontal cortexes can represent both emotional valence and approach/avoid. Increased activity in the left hemisphere can be interpreted as positive valence and approach. Increased activity in the right is taken as negative valence and avoid.1 But what about the emotional states that are more complex, like anger? Anger is an emotion associated with negative valence, yet increased approach motivation. In the case of anger, the EEG shows increased left hemisphere activity, yet we know the negative valence should show activity in the right. Therefore the only useful thing we can pull from the EEG is approach/avoid motivation. It is the only piece of information we can safely assume to be correct when looking at two variables along a single dimension. EEG is our not-so-bright employee.
So, what we need to do is to hire a new employee who thinks in more than one dimension. Here at HCD research, we use EMG (electromyography) to look at emotional valence independent of approach/avoid, which can be measured via heart rate. On top of that, we throw bananas into the mix and add on galvanic skin response as a third dimension, indicating arousal. With a clear picture of what each one of our psychophysiological methods measures specifically, we can generate a detailed and insightful map of complex human emotions.
Human beings are complicated creatures. One of the gravest mistakes that we can make in neuroscience is the oversimplification of very complicated processes. Granted, I just used fruit to explain how emotions work, but this is just a means to scratch the surface of a monumental problem. Even if we were to understand completely how the human brain works, there are still individual differences that further confuse things. (For example, each person has their own unique frontal asymmetry corresponding to their general emotionality.)
The best approach is to start from the ground up, building a foundation in sound research. Taking shortcuts to offer clients more impressive information results in oversight of conflating factors and overgeneralization of intricate details. Though EEG may be flashy and hi-tech, it is ultimately unreliable, ill-suited, and basically unnecessary for our goals in understanding emotion. There still is much we can discover using alternate means of obtaining biometric information.
This is not to say that EEG is downright terrible and should never be used for anything. There are many clinical applications for EEG, which include: finding out whether or not a paitent has had a seizure, testing for brain death, and in some cases, giving a prognosis for patients in comas. In psychophysiology, frontal asymmetry can be used to indicate depression in an individual.2 But in a neuromarketing setting, the only practical use of EEG is to measure approach/avoid motivation, and measuring heart rate is an easier method of doing the same thing. At HCD Research, we choose the appropriate method based on the type of research being done. We are not a technology company selling gadgets; we are a customized market research company.
[HCD Research’s methods of obtaining information about emotion.]
[An example of HCD’s capabilities in mapping emotion. Test samples reflect data recorded from actual participants. Benchmarks represent real data values that correspond to conceptual emotions (Happy, Glad, Etc.)]
1Coan, James A. and Allen, John J. B. “The State and Trait Nature of Frontal EEG Asymmetry in Emotion.” The Asymmetrical Brain. Ed. Kenneth Hugdahl, Ed. Richard J. Davidson. Cambridge: MIT, 2003. 565-615. Print. 2Gotlib, Ian H., Ranganath, Charan, and Rosenfeld, J. Peter. “Frontal EEG Alpha Asymmetry, Depression, and Cognitive Functioning.” Cognition and Emotion 12.3 (1998): 449-478. Print.